[ELGIS] POLL: 12 bit JPEG compression in TIFF

[Volker Fröhlich]

Dear Peter!

You might be interested in these two scratch packages.

https://bugzilla.redhat.com/show_bug.cgi?id=660024

More current version 0.9.2 is somewhat packaged here -- very rough around the 
edges: http://www.geofrogger.net/review/epsilon-0.9.2-1.fc15.src.rpm

I tried to build with MPI support, which is terribly complicated to me and I 
can't recall which state it was in, when I left off.

Please notice that "epsilon" is the appropriate name. I erroneously called the 
elder version "libepsilon".

Volker

Am Samstag, 13. August 2011, 17:40:51 schrieb Peter Hopfgartner:
> I'll start next week some tests on this topic. I would like to
> include epsilon for wavelet compression. This might get similar
> results as ECW.
> 
> Peter
> 
> --------Micha Silver  wrote--------
> 
> Subject: Re: [ELGIS] POLL: 12 bit JPEG compression in TIFF
> 
> Date: 12.08.2011 12:07
> 
> > On 02/08/2011 12:01, Peter Hopfgartner wrote: On
> > 
> > > 08/02/2011 09:01 AM, Mathieu Baudier wrote:
> > >   I do not know of any direct drawback,
> > >   
> > > > > except that internal libjpeg and
> > > > > 
> > > > >  libtiff/libgeotiff are used, instead of the system shared libs.
> > > > >  Frank Warmerdam advised against using the internal
> > > > 
> > > > libtiff back in October 2010:
> > > >  http://lists.osgeo.org/pipermail/el/2010-October/000119.html [1]
> > > >  (the same would probably apply for libjpeg I guess)
> > > >  We could think about a separate gdal, e.g. gdal-il,
> > > 
> > > package with internal libs, with bigTIFF and 12 bit enabled. BTW,
> > > UbuntuGIS is using internal libs, too.
> > 
> > Hi Peter:
> > 
> > I did a quick (amateur) test of jpeg 12 this morning and I must say I
> > was surprised with the results. I started with a 1.4 GB tiff ortho
> > photo, which I also have as an ECW image. The ECW is about 64MB.
> > 
> > I used the OSGeo4W installation of gdal with the libjpeg that
> > supports 12 bit, and I made two compressed tiffs. The regular jpeg
> > compression came down to about 75 MB, a bit larger than the ECW, but
> > it's quality was a bit fuzzy with color changes in the pixels. (Of
> > course ECW is also lossy, introducing changes in the pixel coloring,
> > but keeping \"sharpness\").
> > 
> > The 12 bit jpeg-compressed tiff came down to about 120 MB, only twice
> > the size of the ECW, but it was almost indistinguishable from the
> > original tiff! Both in coloring and sharpness. That was very
> > impressive, I must say.
> > 
> > I don't know where the jpeg2000 format is going (if anwhere). For now
> > this 12-bit jpeg compression looks like an ideal alternative to
> > struggling with the closed ECW format on one hand, or the unwieldy
> > file sizes of uncompressed tiff on the other.
> > 
> > Best, Micha
> > 
> >   Peter
> >   
> > >  _______________________________________________
> > >  el mailing list
> > >  el at lists.osgeo.org [2]
> > >  http://lists.osgeo.org/mailman/listinfo/el [3]
> > >  
> > >  This mail was received via Mail-SeCure System.
> 
> Links:
> ------
> [1] http://lists.osgeo.org/pipermail/el/2010-October/000119.html
> [2] mailto:el at lists.osgeo.org
> [3] http://lists.osgeo.org/mailman/listinfo/el